Uncontaminated potable water is essential to all animal and plant life. In most environments, ample supplies of potable water are readily available for residential, commercial, and agricultural purposes.
However, in many areas of the world, and during natural disasters and emergencies, available water may contain contaminants such as waterborne bacteria, viruses and cysts. These contaminants present serious health risks to persons who would drink such untreated, available water. In addition, persons who are living or working outside of established urban or rural communities, including hikers, outdoorsmen, travelers, and soldiers, may also experience shortages of potable water. In all such cases, there is a need for a portable, lightweight, reusable, device that can be used by one or more persons to immediately and easily purify water that contains potentially harmful microbiological contaminants.
Various types of portable water filters and water purification devices are known, including many straw-like devices. The user may place his mouth over one end of the device, so that he can draw and ingest the water. The other end of the device is immersed in the water source. The user sucks water upward through the device, in the same manner as with a conventional drinking straw, causing the water to pass through the device and contact one or more filtration media.
Some of the known water filter devices include those shown and described in United States Patent Application Publication Nos. 2004/0112826 to Chiba and 2008/0105618 to Beckius. One known water purification device is shown in U.S. Pat. No. 8,318,011. While these devices are said to be generally suitable for their purposes, there appears to be a market demand for a new, proven and tested water purification device that overcomes functional limitations of the devices.
For example, a significant limitation with such prior art, water filtering and purification devices relates to the pore size (measured in microns) required to exclude various and/or specific contaminants from passing through the filter media. Expressed in simple terms, the smaller the pore size of the filtration media, the more microbial and other contaminants will be removed from the water passing through the filter media.
Conventional straw-type water filter devices can only be designated as water filters and cannot be designated as water purifiers. This is because the minimum pore size that allows a user to practically and easily move the water upward through the water filter by mouth suction (0.05 microns) is small enough to trap waterborne bacteria and cysts, but not small enough to trap waterborne viruses. And the ability to trap waterborne viruses is an EPA and NSF/ANSI requirement for a device that may be designated as a water purifier, rather than a water filter.
Similarly, hand-held or gravity feed water purifiers that use filtration media with a pore size capable of trapping waterborne viruses (0.02 microns or less) require gravity feed pressure or pump pressure to move the contaminated water through the small pore sized filtration media. Therefore, while such devices can and do meet water purifier standards, they cannot be used as a straw, or with a hydration backpack that require mouth suction.
A potential health problem arises with such water filters in general, as well as water purifiers that rely on small pore size to trap waterborne viruses and contaminants. Particularly, water filters and small-pored purifiers trap contaminants, allowing contaminant-free potable water to exit such devices. However, the contaminants removed by the filters or purifiers, including bacteria, viruses and cysts, are trapped by and remain within the device. This raises the potential of the on-going growth of these remaining contaminants in the wet and often warm environment of the filter or purifier.
Additionally, smaller pore size filters become clogged more easily and therefore will become quickly ineffective with high sediment water. As a result, unless their filters can be readily changed or cleaned, such devices must be replaced with a new device as soon as they become clogged. The need to maintain a supply of such replacement devices can be extremely problematic in disasters, emergencies and in emerging nations. It is preferable to have access to a device that is maintenance-free over long periods of time and with the ability to clean large amounts of contaminated water.
Known portable water purifiers relying on small pore size to exclude waterborne viruses have other shortcomings. Such water purifiers need rely upon gravity feed pressure or pump pressure to move the contaminated water through the filtration media having these small pores, and thus suffer from relatively slow flow rates.
Other types of water filtering and water purifying devices are known, but they are typically inconvenient to operate, requiring set-up or preparation time, or are bulky to carry and operate, and are therefore not truly portable.
The inventor has identified the numerous problems associated with existing portable water filtering and water purifying devices. As a result of over twenty-five years of commercial experience with personal and portable water purifiers, as well as a significant amount of experimentation, the inventor has now developed a straw-style water purification apparatus that overcomes the limitations of prior art water filters and water purifiers.